Kaylie & Matt investigate latent heat of fusion

At the time of this story, in 2001, I was a propationary year teacher. Encouraged to use open-ended experiment as a teaching method, I asked my class of ten year old year-5 pupils to investigate what happens over time to water placed in the freezer compartment of a refrigerator.

Each was given a spike-and-dial thermometer, and there were also five Xemplar PocketBooks (small, relatively inexpensive, rebadged Psion handheld computers; many similar machines are available now) available on a first-come, first served basis.

The PocketBook offer was taken up on only one machine - by Kaylie and Matt, a friendship-pair living in the same street. Assessed as being close to the bottom of the class ability range, their motivation for volunteering seemed a mixture of laziness and novelty interest. Accustomed to paper and coloured pens myself, I paid little attention to the low IT take-up.

Observation sheets were prepared in class, the plotting of results on graph paper discussed and practised. Matt and Kaylie sought help with design of a spreadsheet and, by the end of the lesson, had a computerised record form with automatic, auto-scaled plotting. Most of the pupils were, at this stage, interested in the experiment and eager to get started. I advised thermometer readings at roughly 15 minute intervals, then sent them home to experiment.

When they returned after the weekend, the difference in educational outcomes between paper and spreadsheet was marked.

Data were patchy, invariably oversampled in the first hour or so but increasingly sparse thereafter. Plotting had generally been abandoned early on. It seemed that my foray into experiential learning was a failure.

Kaylie and Matt, however, had been drawn by the automatic plot into enthusiastic continuous monitoring of the temperature curve. Matt said, in his write up: “we thot the flat bits was weird, so we looked then to see what it looked like. Then we looked again ever time it moved again.”

Conclusions drawn by most of the pupils were limited to a single figure (although it varied considerably from pupil to pupil) for the time taken freeze solid. Kaylie, having watched the data assemble, said that the water “nearly froze in about two hours, but then it stopped and thought about it for a long time.” I prompted with questions about what happened before and after the water froze; most of the class said “nothing” but Matt disagreed, saying that it “jiggled about”; Kaylie added that it “kept stopping and starting.”

The pair asked permission to import their handheld data into a desktop spreadsheet for examination during their lunch hour. Returning later, I was startled to find that these two supposedly low-ability pupils had entered all of the class data on their own initiative, plotting multiple graphs for comparison with their own. In an impromptu presentation to their class mates, they took over my role in the lesson to showed considerable insight into the probable significance of similarities and differences between the graphs. They had also merged the sheets (inventing x-wise data transformation in the process) and were eager to discuss the implications of model which they perceived in the resulting scatter graph. I had learned a lesson of my own; I now start any similar activity from computerised methods, rather than working up to them.

[contributed by Chandra]